We had to store our AS for a couple of months outdoors in Georgia. When we left, the charging controllers was showing that it was charging. Our batteries were at 13.8V. We had turned off everything except the "kill switch" When we got back, out batteries was only showing 7.9V. Obviously the solar system stopped charging while it was sitting in storage. After plugging into AC power, the converter charged the batteries, but the solar is not charging even on a sunny day. Our controller has a diode and fuse in line to the batteries. Any insights?

Take a 12v meter and test the input side of the controller for voltage. If there is no voltage then there is an issue with the panel, connections or wires. If there is voltage then test the output or battery side. If voltage is showing on the input but not output then the issue is with the controller. If there is voltage on both sides then test the connections where the output wires terminate. You should see almost the same voltage and to the battery connections. If not then check that fuse. If all looks well then the batteries are suspect.

Since you batteries got totally discharged then it may be a better idea to pull them out and put them on a separate battery charger to see if you can salvage them. Purchase a hydrometer to test each cell (if they are flooded cell batteries). If any of them are bad then its time to replace both batteries.

If you can post the solar panel size, controller make and model and battery make and model.

The previous poster has got it right about trouble shooting.
The same thing happened to me. It turned out to be batteries.
Unless there is a current drain somewhere in your trailer, good batteries are not going to fail in a couple of months even if they are not being charged by solar.

Take a 12v meter and test the input side of the controller for voltage. If there is no voltage then there is an issue with the panel, connections or wires. If there is voltage then test the output or battery side. If voltage is showing on the input but not output then the issue is with the controller. If there is voltage on both sides then test the connections where the output wires terminate. You should see almost the same voltage and to the battery connections. If not then check that fuse. If all looks well then the batteries are suspect.

Since you batteries got totally discharged then it may be a better idea to pull them out and put them on a separate battery charger to see if you can salvage them. Purchase a hydrometer to test each cell (if they are flooded cell batteries). If any of them are bad then its time to replace both batteries.

If you can post the solar panel size, controller make and model and battery make and model.

Kelvin

GOOD post done right.

__________________Jimmini : AKA : TUMBLEWEED. Just an old buzzard with a itch to yonder. Cowboys have a way of looking at things a little differently than most folks.Their wisdom is simple and more down to earth.

We had to store our AS for a couple of months outdoors in Georgia. When we left, the charging controllers was showing that it was charging. Our batteries were at 13.8V. We had turned off everything except the "kill switch" When we got back, out batteries was only showing 7.9V. Obviously the solar system stopped charging while it was sitting in storage. After plugging into AC power, the converter charged the batteries, but the solar is not charging even on a sunny day. Our controller has a diode and fuse in line to the batteries. Any insights?

I plugged in a Solar panel to my system last summer while the trailer was on a lot for sale. That was the first time I had used this set of Solar panels. Was in a hurry and just plugged it. Didn't check the polarity of the plug and it destroyed my battery and blew some fuses. Make sure the Polarity is correct.

Dumb me. I am a master electrician and should have known to check the polarity, so much for being in a hurry.